**Describe the bug** When trying to use the router option in a mocha + chai project, it fails with `TypeError: VueRouter is not a constructor` **To Reproduce** Run unit tests: https://github.com/FCalabria/testing-library-mocha The same project with jest, works perfectly. **Related information:** - `@testing-library/vue` version: 4.1.0 - `Vue` version: 2.6.10 Changing the way to import the library fixes the bug, but breaks it for jest ```javascript const VueRouter = require('vue-router') // current code, works with jest const VueRouter = require('vue-router').default // fix for mocha, breaks jest ```